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ORIGINAL ARTICLE
Synthesis and characterization of carbon nanotubes over ironcarbide nanoparticles coated Al powder using thermal chemicalvapor deposition
S. K. Singhal • R. K. Seth • Rashmi •
Satish Teotia • Mamta • Rajeev Chahal •
R. B. Mathur
Received: 17 November 2011 / Accepted: 6 February 2012 / Published online: 22 February 2012
� The Author(s) 2012. This article is published with open access at Springerlink.com
Abstract A simple method is described to synthesize
carbon nanotubes (CNTs) by the thermal decomposition of
toluene at 750�C over a thin catalyst film deposited on Al
powder. This method allows the bulk metal surface to act
as both the catalyst and support for CNT growth. The
catalyst film on Al was prepared from an ethanol solution
of iron nitrate. Under the growth conditions, iron nitrate
formed an amorphous iron oxide layer that transform into
crystalline Fe2O3, which was further reduced to Fe3O4 and
Fe3C. It is believed that the growth of CNTs took place on
iron carbide nanoparticles that were formed from FeO. The
characterization of CNTs was mainly carried out by pow-
der X-ray diffraction and scanning electron microscopy,
X-ray fluorescence and thermogravimatric analysis. The
CNTs were found to be highly dispersed in Al powder.
This composite powder could be further used for the fab-
rication of Al matrix composites using powder metallurgy
process in which the powder were first cold pressed at
500–550 MPa followed by sintering at 620�C for 2 h under
a vacuum of 10-2 torr. The mechanical properties of the
sintered composites were measured using a microhardness
tester and a Universal testing Instron machine.
Keywords Carbon nanotubes � Thermal chemical vapor
deposition � Metal-matrix composites
Introduction
Since the discovery of carbon nanotubes (CNTs) (Iijima
1991), these nanotubes have been used in a variety of
applications because of its unique properties, e.g. low
density ranging from 1.2 to 1.8 g/cc, high stiffness (*970
GPa), high thermal conductivity up to 3,000 W/mK, large
aspect ratio (1,000–10,000) and high specific strength of
55.5 GPa (Ajayan 1999; Kim et al. 2001; Treacy et al.
1996; Yu et al. 2000). The unique mechanical properties of
carbon nanotubes make them promising reinforcements for
synthesizing light-weight, high-strength composites for
various applications. Although Al composites are mainly
used in aerospace and automobile sectors to fabricate many
components because of its lower density (a requirement
necessary for the weight reduction for many components
thereby saving fuels and hence energy), pure Al composites
have not found to possess high mechanical strength, and,
are, therefore, alloyed with a number of other metals to
improve the mechanical properties. For the last one decade,
many researches all over the world are trying to increase the
mechanical properties of Al composites by reinforcing it
with suitable binders, so that its strength could be improved
significantly. In the recent years, several researchers are
involved in the development of CNTs reinforced Al- matrix
composites. The combination of unique properties of CNTs
and Al has substantial potential in many weight sensitive
applications although still considerable research is required
to identify optimal processing route.
Till now, a few successful studies on CNTs reinforced
Al matrix composites have been reported (Morsi et al.
S. K. Singhal (&) � R. K. Seth � Rashmi � R. B. Mathur
National Physical Laboratory, Council of Scientific
and Industrial Research, Dr. K.S. Krishnan Road,
New Delhi 110012, India
e-mail: sksinghal@mail.nplindia.ernet.in
S. Teotia � Mamta
Guru Jambeshwar University of Science and Technology,
Hisar, India
R. Chahal
Punjab University, Chandigarh, India
123
Appl Nanosci (2013) 3:41–48
DOI 10.1007/s13204-012-0066-z
2010; Wang et al. 2009; Singhal et al. 2011; George et al.
2005; Bustamante et al. 2008; Laha et al. 2009; Zhou et al.
2007; He et al. 2007; Tokunaga et al. 2008; Lahiri et al.
2009), which are mainly attributed to the processing dif-
ficulties and lack of understanding of the strengthening
mechanisms. Different methods, such as powder metal-
lurgy (Morsi et al. 2010; Wang et al. 2009; Singhal et al.
2011; George et al. 2005; Bustamante et al. 2008), plasma
spray forming (Laha et al. 2009), liquid infiltration (Zhou
et al. 2007), molecular level mixing (He et al. 2007), high
pressure torsion (Tokunaga et al. 2008) and roll bonding
followed by annealing (Lahiri et al. 2009) etc. have been
tried for the development of CNTs reinforced Al com-
posites; of all these methods; however, PM route has been
found to be very effective as using this route, composites of
any shape and size could be easily fabricated. In this
method, generally a mixture of Al powder and CNTs (taken
in a predetermined weight ratio) is first cold pressed in a
hardened steel die of any desired size and shape to make a
green disc and then sintered either in an inert atmosphere
(N2, Ar, etc.) or under a vacuum of about 10-2 torr at
temperatures below the melting temperature of Al (660�C).
However, one of the major problems in this method is the
homogeneous dispersion of CNTs in Al powder, because of
the density difference between Al and CNTs and also the
strong van der Waal’s force of attraction between the walls
of the tube. Because of this force of attraction between the
CNTs, they tend to agglomerate rather than to disperse in
Al matrix. In addition because of the large difference in the
densities of Al (2.7 g/cc) and CNTs (1.4–1.8 g/cc) and also
thermal mismatch it is very difficult to obtain a homoge-
neous mixture of Al powder and CNTs. Further, it is well
known that the Al powders are hardly sinterable materials
because of the oxide layers on its surface. This layer has to
be broken up to achieve high packing density. Thus, the
key factors for the fabrication of CNTs reinforced Al
composites are (1) the homogeneous CNTs distribution and
retention of its original structure, (2) sufficient adhesion at
the matrix interface for effective load transfer. Therefore,
for the past few years, efforts have been made to disperse
CNTs in Al matrix using a number of process, including
high energy ball milling (Esawi and Morsi 2007), molec-
ular level mixing (He et al. 2007), nanoscale dispersion
using natural rubber (Noguchi et al. 2004), acid function-
alized CNTs (Deng et al. 2007), use of some surfactants,
such as sodium dodecyl sulfate, etc. (Zhang and Gao 2007).
Although a great success has been achieved using some of
these methods, the dispersion of CNTs in Al powder is still
not achieved up to a satisfactory level, and there is need to
modify these methods or to discover some new methods for
the better distribution of CNTs in Al matrix. Some of the
results obtained on Al-CNTs composites, it has been found
that the weight percentage of carbon nanotubes in Al
matrix should be in the range 0.5–3.0 wt% to obtain
composites having high micro hardness, tensile/compres-
sive strength and other properties (Sridhar and Karthic
2009). Therefore, a controlled weight percentage of CNTs
in Al powder is essential to obtain the optimal results.
Although the molecular level mixing has been found to be
very effective for the homogeneous dispersion of CNTs in
Cu matrix, this method is not very effective for obtaining a
homogeneous dispersion of CNTs in Al matrix (He et al.
2007). A homogeneous mixture consisting of CNTs (Ni)-
Al powders was prepared using a combination of CVD,
calcinations and reduction in [Ni(OH)2/Al] (He et al.
2007). However, the composite fabricated from this com-
posite powder was always contaminated with Ni nanopar-
ticles. In the present method, we have grown CNTs directly
on Al powder using thermal chemical vapor deposition
(CVD) by the decomposition of toluene at 750�C in the
presence of Fe3C thin catalyst-layer deposited over Al
powder. The composite powder thus produced could be
used for the fabrication of Al matrix composites.
Experimental
Materials
All chemicals of analytical grade were purchased from
Fisher Scientific (India).
Preparation of a thin layer of iron nitrate on Al powders
To deposit a thin layer of iron nitrate on Al powders, the
aluminum powder was first ball milled for 10 h at 200 rpm
using stainless steel balls of diameter 10 mm. The balls to
powder weight ratio was kept constant at 10:1. Also milling
was carried out in the presence of Ar gas and 2 wt% stearic
acid which prevented the oxidation and agglomeration of
Al nanopowder. A small quantity of this powder was added
to an ethanol solution of iron nitrate (1 wt%) and the
mixture was first sonicated for 4 h and then dried at 80�Cusing a magnetic stirrer. A thin layer of iron nitrate was
found to deposit on the surface of Al powder.
Growth of carbon nanotubes on Al powders
A thermal CVD was used for the growth of CNTs on Al
powder having a thin layer of iron nitrate. The details of
CVD process has been described elsewhere (Mathur et al.
2008). A mixture of toluene and ferrocene was used as the
precursor for the growth of CNTs, and Ar was used as the
carrier gas. The growth of CNTs from the decomposition of
this mixture was observed at 750�C. However, as the
melting temperature of Al is 660�C, Al powder having a
42 Appl Nanosci (2013) 3:41–48
123
thin layer of iron nitrate was kept in a quart boat at the end
of the reactor where the temperature was calibrated to
600�C. The deposition time was varied from 0.5 to 1.5 h.
Fabrication of Al-CNTs composites
To fabricate the composites, the CVD-coated Al powder
was further blended with a predetermined weight percent-
age of pure and milled Al powder at 350 rpm for 2 h in the
presence of Ar gas. The weight percentage of Al was
adjusted so that in the final mixture the CNTs is 1.5 wt% of
the total weight of the sample. A homogeneous mixture of
Al and 1.5 wt% CNTs were pressed in the form of a cir-
cular disc (diameter 6.0 mm) and a rectangular shaped
(length 45 mm, width 8 mm). The circular shaped samples
were mainly used for microhardness, compressive strength
measurements (as per ASTM standards) and other char-
acterizations, such as formation of phases formed during
the sintering conditions and morphology of the composites
were carried out on rectangular shaped samples. All sam-
ples were first cold pressed at a constant pressure of
550 MPa and then sintered at 620�C for 2 h under a vac-
uum of 10-2 torr. The heating and cooling rates were
adjusted to 20 and 10�C/min, respectively. For comparison,
composites under similar processing conditions were also
fabricated using pure Al powder. All sintered composites
were polished using a fine diamond paste and various
mechanical and other characterizations were made.
Instrumentation
A scanning electron microscope (SEM, model LEO 440)
equipped with an energy-dispersive spectrometer (EDS,
model Oxford Link ISIS 300) was used to study the growth
and morphology of CNTs on Al powder. Microstructural
characterization at high magnifications of the CNTs pro-
duced by CVD were carried out using a transmission
electron microscopy (TEM, model JEOL JEM 200 CX),
operated at the electron accelerating voltage of 200 kV.
A FEI model Techani G2 F30 STWIN, 300 kV machine
was used to carry out high-resolution transmission electron
microscopy (HRTEM). Growth of CNTs on Al powder was
also estimated by thermogravimetric analysis (TGA) using
TGA DSC 1/1600/LF, Mettler Toledo, Switzerland. For
this purpose, a known weight of CNTs grown Al powder
was heated in air very slowly (10�C/min) up to a temper-
ature of 600�C (below the melting temperature of Al) and
the weight loss was determined. The flow rate of air was
kept constant at 100 ml/min. Almost all the CNTs are
oxidized at *450�C and the loss in weight of the sample
correspond to the amount of CNTs grown on Al powder
using CVD. Quantitative elemental analysis of the sample
was also carried out using Rigaku ZSX Primus Wavelength
Dispersive X-ray Fluorescence Spectrometer (WD-XRF).
The spectrometer has a Rh-target, end-window, 4 kW,
sealed X-ray tube as the excitation source and scintillation
(SC) for heavy elements and flow proportional counter
(F-PC) for light elements as the detectors. Specimen for the
XRF measurements was in the form of a pellet prepared
from the powder sample at a pressure of about 500 MPa.
Measurements were made at a temperature of 36.5�C under
vacuum. The Ka X-spectral lines were recorded at a tube
rating of 30 kV and 100 mA, using F-PC and analyzer
crystals RX61 (C Ka), RX35 (O Ka) and PET (Al Ka).
The X-ray diffraction (XRD) analysis of the compos-
ites fabricated in the present work was carried out by
means of Rigaku D/MAX-2400 X-ray diffraction analysis
(Rigaku Corp. Tokyo, Japan) using CuKa radiation
(k = 0.15418 nm) at room temperature. Microhardness
measurements on the composites was carried out on a
Zwick 3212 (Germany) hardness tester under a load of
100 g for 15 s dwell time and a universal testing Instron
machine (Model 4041) was used to study the various
mechanical properties.
Results and discussion
Figure 1a and b shows a typical transmission electron
microscopy (TEM) images of CNTs grown on Al powder
from a mixture of toluene and ferrocene at 750�C using
CVD (Mathur et al. 2008). The diameter of the synthesized
CNTs was 50–100 nm and length several microns. Most of
the CNTs are of uniform size and cylindrical morphology.
Figure 1c and d shows an SEM image of Al powder con-
taining CNTs deposited on its surface at 600�C for a
duration of 1.5 h using the above-mentioned CVD process.
Figure 1d is the SEM image at high magnification. The
CNTs were found to disperse well in Al powder. From the
EDS analysis (Fig. 2), it was observed that the concentra-
tion of CNTs grown on Al powder was *6 wt%. Figure 3a
shows another SEM micrograph of Al powder coated with
CNTs at 600�C for a duration of 1.5 h. CNTs grown on Al
powder are clearly seen as shown in the encircles. The EDS
analysis (Fig. 3b) of this composite powder showed
*7 wt% of C corresponding to CNTs. However, as the
EDS has been done on a very small localized region the
quantitative estimation of carbon. To obtain more reliable
quantitative data on the growth of CNTs on Al powder
thermogravimetric (TGA) and X-ray fluorescence (XRF)
analysis were carried out. Figure 3c shows a TGA spec-
trum of the same sample of CNTs coated Al powder at
600�C for a duration of 1.5 h. The mixture of CNTs-coated
Al powder was heated in air up to a temperature of 600�C
Appl Nanosci (2013) 3:41–48 43
123
(below the melting temperature of Al) and the weight loss
was estimated. Almost all the CNTs present in Al/CNTs
mixture were found to oxidize at a temperature of about
485�C. From the weight loss, it was estimated that the
weight percentage of CNTs grown on Al powder was
4.25%.
Fig. 1 a, b TEM image of CNTs grown on Al powder by CVD. SEM micrographs of CNTs grown on Al powder from a mixture of toluene and
8 wt% ferrocene. c At low and d at high magnification (deposition time 1 h)
Fig. 2 EDS spectra of CNTs
grown on Al powder by CVD
44 Appl Nanosci (2013) 3:41–48
123
Figure 4a–c shows the XRF spectra of the same sample
of CNTs coated Al powder used for TGA analysis. The
peaks at 2h * (a) 32.5� (b) 50.8� and (c) 144.7� correspond
to C Ka, O Ka and Al Ka spectral lines respectively, thus
confirming the presence of C, O and Al elements in the
composite powder. From this figure, it is seen that the
weight percentage of C (corresponding to CNTs) was 3.95%,
which was almost equivalent to that observed in TGA
analysis shown in Fig. 3a. However, these mixtures of Al
and CNTs could not be found suitable for the fabrication of
Al matrix composites using powder metallurgy process as
the optimum concentration of CNTs in Al powder were
found to be 0.5–2 wt% for the optimum results (Sridhar
and Karthic 2009). Hence, a detailed and systematic study
was made further to deposit only a small concentration of
CNTs on Al powder using thermal CVD by varying dif-
ferent process parameters, such as weight percentage of
ferrocene in toluene, reaction temperature, duration of
reaction, flow of carrier gases, weight percentage of iron
nitrate in Al powder and so on, so that it could be used
further for the fabrication of Al-CNTs composites with
optimum properties. To increase the dispersion of CNTs in
Al powder, the mixture was further blended with pure and
milled Al powder at 350 rpm for 2 h in the presence of
stearic acid (used as a process control agent). Milling in the
presence of a process control agent enables a balance
between fracture and welding to be established, enabling
refinement of the powder particle size. Further, in addition
to prevent the excessive welding of Al powders, it also
reacted with Al leading to the formation of second phases,
such as c-Al2O3 (JCPDS: 10-0425 1999) and/or Al4C3
(JCPDS: 34-0799 1999).
It must be mentioned that during the high energy ball
milling of Al/CNTs powder with pure Al, a desired con-
centration of CNTs in Al powder could be obtained. Fig-
ure 5a and b shows SEM micrographs of CNTs coated on
Al powder after 1.5 h deposition time from a mixture of
toluene and 8% ferrocene at 600�C followed by blending
for 2 h in the presence of 2 wt% stearic acid. The CNTs
were found to be highly dispersed on the entire surface of
Al powder.
Figure 6 shows a typical XRD pattern of Al-CNTs
composite powder using CVD followed by blending for
4 h. The XRD peaks of CNT (002) and (004) planes at
2h = 26 and 44� could be clearly seen in this pattern along
with Al, Fe3C and Fe3O4. From the various phases formed,
we can deduce that under the growth conditions iron nitrate
thin layer coated on Al powder is slowly decomposed to
Fe2O3 in the presence of excess of nitrogen. Fe2O3 crystals
are reduced to some intermediate oxides (Fe3O4, FeO, etc.)
by the hydrogen released from the pyrolysis of toluene.
Fig. 3 a SEM micrograph of CNTs grown on Al powder after 1.5 h
deposition using CVD. b EDS spectrum of CNTs coated Al powder
(1.5 h deposition time). The inset shows the wt% of different
constituents of the composite powder. c TGA of Al/CNTs composite
powder
Appl Nanosci (2013) 3:41–48 45
123
FeO is finally transformed into metastable Fe3C. Formation
of Fe3C provides active nucleation sites for the growth of
CNTs on Al powder, and as the concentration of iron
nitrate increases, the formation of such potential nucleation
sites also increases. Thus, a high density of CNTs on Al
powder was observed using the present method. It must be
mentioned that the growth of CNTs was also observed on
stainless steel (Baddour et al. 2008). In this experiment,
CNTs were grown on stainless steel powder by passing
C2H2 gas over steel powder (taken in a quartz boat) kept in
a quartz furnace at a temperature of about 750–800�C.
Nanoparticles (Fe) from stainless steel powder acts as a
catalyst and the deposition of CNTs was observed on the
entire surface of steel powder. Stainless steel seems to be
an effective candidate for CNTs growth due to its high iron
content (*66%) and the possibility to tailor active sites for
the growth process. However, in this experiment, no sys-
tematic study has been made to control the growth of CNTs
on steel powder, and thus, no data are available on the
concentration of CNTs deposited or grown on stainless
steel powder.
In the present method, we tried to grow CNTs directly
on Al powder by placing it in a quartz boat kept at a
temperature of about 600�C (below the melting tempera-
ture of Al *650�C) near the end of the reactor. A mixture
of toluene and ferrocene was fed from one of the quartz
reactor into the central zone where the temperature was
around 750�C. Ar was used as the carrier gas. This tem-
perature was found to be necessary for the growth of CNTs.
However, our initial experiments did not show any growth
of CNTs on the surface of pure Al powder. Therefore, we
modified the process and used a mixture of Al powder
containing 1.0 wt% iron nitrate (Fe(NO3)3�9H2O) instead
of pure Al powder. From our earlier work, it is reported
that a high growth of CNTs can be obtained from the
decomposition of toluene at 750�C in the presence of fer-
rocene, used as a catalyst (Mathur et al. 2008). Using this
mixture, a very high growth rate of CNTs was observed on
Al powder containing about 1 wt% iron nitrate at 600�C.
To use this composite powder useful for the fabrication
of composites, it was blended at 350 rpm with pure and
milled Al powder for another 2 h in the presence of stearic
acid keeping the ball to powder weight ratio of 10:1. The
weight percentage of Al was estimated so that in the final
mixture the percentage of CNTs is *1.5 wt% as already
optimized by earlier researchers (Sridhar and Karthic
Fig. 4 XRF spectrum of CNTs coated on Al powder using thermal CVD
46 Appl Nanosci (2013) 3:41–48
123
2009). The blended mixture was cold pressed at 550 MPa
followed by sintering at 620�C for 2 h under a vacuum of
10-2 torr. The samples were fabricated in accordance to
ASTM standards, so that various mechanical tests could be
made. Before characterization, the sintered composites
were polished well using a fine diamond paste. The
microhardness tests were carried out in accordance with
ASTM Standard E-384. Samples for measuring compres-
sive strength were prepared as recommended by ASTM
Standard E9. Three point bending strength were prepared
as per ASTM standard E 399-90S. At least 10 sets of
results were obtained for each test to confirm the repeat-
ability of the results. The average microhardness of some
of the composites fabricated in the present work was about
200 ± 10 kg/mm2, which is much higher than the hardness
values reported earlier. Similarly other mechanical prop-
erties, such as compressive strength of the composites
using the composite powder synthesized in the present
method was also found to be 280 ± 10 MPa which is much
higher to those obtained using pure Al powder (100 MPa).
Hence, it can be concluded that the present method could
be used for the fabrication of Al matrix composites with
improved mechanical properties. The mechanical proper-
ties of Al composites increases with the addition of CNTs
because of the load sharing between Al matrix and CNTs.
CNTs can withstand much higher loads than Al matrix and
hence there is a substantial increase in the mechanical
properties of the composites. Homogeneous dispersion of
CNTs in Al matrix is the key factor in the fabrication of
composites. If CNTs agglomerate at one site then that area
will receive the maximum load and hence formation of
cracks will be seen at that point, and also the rest of the
composite will not be able to withstand heavy loads due to
lack of load transfer to CNTs and the whole structure will
collapse. It is, therefore, extremely important to have a
highly dispersed system so that the load sharing is done in
an even manner minimizing the load in a single area, dis-
persing the load evenly and hence increasing the total load
that a composite can withstand. The present method is
believed to provide a highly dispersed system, where we
can achieve a homogeneous dispersion of CNTs in Al
matrix using thermal CVD combined with high energy ball
milling and thus can be used for the fabrication of com-
posites with improved mechanical properties.
Acknowledgments The authors are grateful to the Director,
National Physical Laboratory, New Delhi, for his permission to
publish the results reported in this paper. Sincere thanks are due to
Mr. K.N. Sood and Mr. Jai for their help in SEM and EDS charac-
terization of CNTs coated on Al powder.
Open Access This article is distributed under the terms of the
Creative Commons Attribution License which permits any use, dis-
tribution, and reproduction in any medium, provided the original
author(s) and the source are credited.
Fig. 5 SEM micrographs showing high density of CNTs grown on
Al powder (deposition time = 1.5 h). a At low and b at high
magnification
Fig. 6 XRD pattern of Al-CNT composite powder synthesized using
thermal CVD
Appl Nanosci (2013) 3:41–48 47
123
References
Ajayan PM (1999) Nanotubes from carbon. Chem Rev 99:1787–1800
Baddour CE, Fadlallah F, Nasuhoglu D, Mitra R, Vandsburger L,
Meunier JL (2008) A simple thermal CVD method for carbon
nanotubes. Carbon 47:313–347
Bustamante RP, Guel IE, Flores WA, Yoshida MM, Ferreira PJ,
Sanchez RM (2008) Novel Al-matrix nanocomposites reinforced
with multi-walled carbon nanotubes. J Alloy Compd 450:323–326
Deng CF, Wang DZ, Zhang XX, Li AB (2007) Processing and
properties of carbon nanotubes reinforced aluminium compos-
ites. Mater Sci Eng A 444(1–2):138–145
Esawi A, Morsi K (2007) Dispersion of carbon nanotubes (CNTs) in
aluminum powder. Compos Pt A Appl Sci Manuf 38(2):646–650
George R, Kashyap KT, Rahul R, Yamdagni S (2005) Strengthening
in carbon anotubes/aluminium (CNT/Al) composites. Script
Mater 53:1159–1163
He CN, Zhao NQ, Shi CS, Du X, Li J, Li H, Cui Q (2007) An
approach to obtaining homogeneously dispersed carbon nano-
tubes in Al powders for preparing reinforced Al-matrix com-
posites. Adv Mater 19:1128–1132
Iijima S (1991) Helical microtubules of graphitic carbon. Nature
354:56–58
Joint Committee of Powder Diffraction Standards (JCPDS: 10-0425)
(1999) International Centre for Diffraction Data
Joint Committee of Powder Diffraction Standards (JCPDS: 34-0799)
(1999) International Centre for Diffraction Data
Kim P, Shi L, Majumdar A, McEuen PI (2001) Thermal transport
measurements of individual multiwalled nanotubes. Phys Rev
Lett 87:215502–215505
Laha T, Chen Y, Lahiri D, Agrawal A (2009) Tensile properties of
carbon anotubes reinforced aluminum nanocomposite fabricated
by plasma spray forming. Compos Part A 40:589–594
Lahiri D, Bakshi SR, Keshri AK, Liu Y, Agrawal A (2009) Dual
strengthening mechanisms induced by carbon nanotubes in roll
bonded aluminum composites. Mater Sci Eng A 523(1–2):263–
270
Mathur RB, Chatterjee S, Singh BP (2008) Growth of carbon
nanotubes on carbon fiber substrates to produce hybrid/phenolic
composites with improved mechanical properties. Compos Sci
Technol 68:1608–1615
Morsi K, Esawi AMK, Lanka S, Sayed A, Taher M (2010) Spark
plasma extrusion (SPE) of ball-milled aluminium and carbon
nanotubes reinforced aluminium composite powders. Compos Pt
A Appl Sci Manuf 41:322–326
Noguchi T, Magario A, Fukagawa S, Shimizu S, Beppu J, Seki M
(2004) Carbon nanotubes/aluminium composites with uniform
dispersion. Mater Trans 45:602–604
Perez-Bustamante R, Estrada-Guel I, Antunez-Flores W, Miki-
Yoshida M, Ferreira PJ, Martinez-Sanchez R (2008) Novel
Al-matrix nanocomposites reinforced with multi-walled carbon
nanotubes. J Alloys Compd 450:323–326
Singhal SK, Pasricha R, Teotia S, Girish K, Mathur RB (2011)
Fabrication and characterization of Al-matrix composites rein-
forced with amino-functionalized carbon nanotubes. Compos Sci
Technol 72:103–111
Sridhar I, Karthic RN (2009) Processing and characterization of
MWCNT reinforced aluminum matrix composites. J Mater Sci
44:1750–1756
Tokunaga T, Kaneko K, Horita Z (2008) Production of aluminium-
matrix carbon anotubes composite using high pressure torsion.
Mater Sci Eng A 490:300–304
Treacy MMJ, Ebbesen TW, Gibson JM (1996) Exceptionally high
Young’s modulus observed for individual carbon nanotubes.
Nature 381:678–680
Wang L, Choi H, Myoung JM, Lee W (2009) Mechanical alloying of
multi-walled carbon nanotubes and aluminium powders for the
preparation of carbon/metal composites. Carbon 47:3427–3433
Yu MF, Lourie O, Dyer MJ, Moloni K, Kelly TF, Ruoff RS (2000)
Strength and breaking mechanism of multiwalled carbon nano-
tubes under tensile load. Science 287:637–640
Zhang J, Gao I (2007) Dispersion of multiwalled carbon nanotubes by
sodium dodecyl sulfate for preparation of modified electrodes
toward detecting hydrogen peroxide. Mater Lett 61:3571–3574
Zhou SM, Zhang XB, Din Z, Min C, Xu G, Zhu W (2007) Fabrication
and tribological properties of carbon nanotubes reinforced Al
composites prepared by pressure-less infiltration technique.
Compos Part A Appl Sci Manuf 38:301–306
48 Appl Nanosci (2013) 3:41–48
123
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